Prevent exception when glTF has empty joints array
Prevent exception when glTF has empty joints array

RaananW/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js